diff --git a/ext/mbstring/libmbfl/filters/unicode_table_jis2004.h b/ext/mbstring/libmbfl/filters/unicode_table_jis2004.h
index 01afcc1f2d9..c8bc433d349 100644
--- a/ext/mbstring/libmbfl/filters/unicode_table_jis2004.h
+++ b/ext/mbstring/libmbfl/filters/unicode_table_jis2004.h
@@ -1608,7 +1608,7 @@ static const unsigned short ucs_a1_jisx0213_table[] = { // 0x0000 - 0x045f
 0x0040,0x0041,0x0042,0x0043,0x0044,0x0045,0x0046,0x0047,
 0x0048,0x0049,0x004A,0x004B,0x004C,0x004D,0x004E,0x004F,
 0x0050,0x0051,0x0052,0x0053,0x0054,0x0055,0x0056,0x0057,
-0x0058,0x0059,0x005A,0x005B,0x005C,0x005D,0x005E,0x005F,
+0x0058,0x0059,0x005A,0x005B,0x2140,0x005D,0x005E,0x005F,
 0x0060,0x0061,0x0062,0x0063,0x0064,0x0065,0x0066,0x0067,
 0x0068,0x0069,0x006A,0x006B,0x006C,0x006D,0x006E,0x006F,
 0x0070,0x0071,0x0072,0x0073,0x0074,0x0075,0x0076,0x0077,
diff --git a/ext/mbstring/tests/sjis2004_encoding.phpt b/ext/mbstring/tests/sjis2004_encoding.phpt
index cf9ef7a91a7..3278e85dfe5 100644
--- a/ext/mbstring/tests/sjis2004_encoding.phpt
+++ b/ext/mbstring/tests/sjis2004_encoding.phpt
@@ -37,7 +37,10 @@ while ($line = fgets($fp, 256)) {
 	}
 }
 $fromUnicode["\x00\x7E"] = "\x7E"; /* Not reversible; SJIS 0x7E -> U+203E */
-$fromUnicode["\x00\x5C"] = "\x5C"; /* Not reversible; SJIS 0x5C -> U+00A5 */
+
+/* U+005C is backslash, Shift-JIS 0x815F is REVERSE SOLIDUS
+ * (ie. a fancy way to say "backslash") */
+$fromUnicode["\x00\x5C"] = "\x81\x5F";
 
 testAllValidChars($validChars, 'SJIS-2004', 'UTF-32BE');
 echo "SJIS-2004 verification and conversion works for all valid characters\n";